Mechanical plug

ABSTRACT

A mechanical plug includes first and second plug portions and an elongate member. The first plug portion includes a first endwall and a first sidewall. The first sidewall includes a female section extending in a direction along a longitudinal axis of the mechanical plug. The second plug portion is movable relative to the first plug portion. The second plug portion includes a second sidewall, a second endwall coupled to the second sidewall, and a seal. The second sidewall includes a male section extending in a direction along the longitudinal axis. The seal surrounds a portion of the male section in a region along the longitudinal axis between the second endwall and the female section. The elongate member is coupled to the first and second plug portions. Actuation of the elongate member moves the first plug portion and the second plug portion toward each other to compress the seal.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Non-Provisional Pat.Application No. 17/396,202, filed Aug. 6, 2021, which is a continuationof U.S. Non-Provisional Pat. Application No. 16/396,889, filed Apr. 29,2019, which claims priority to U.S. Provisional Pat. Application No.62/664,594, filed Apr. 30, 2018, the entire contents of each of whichare incorporated by reference herein.

TECHNICAL FIELD

The present invention generally pertains to mechanical plugs forconduits.

BACKGROUND

Inflatable plugs are sometimes used for plugging conduits, such as sewerlines, gas lines, or oil pipelines, to permit maintenance, facilitatetoxic waste containment, or remove blockages. However, such plugstypically require coupling to fluid lines to facilitate inflation anddeflation within conduits or multiple seal actuators for larger andhigher pressure plugs.

SUMMARY

In one embodiment, the disclosure provides a mechanical plug forrestricting fluid flow through a conduit. The mechanical plug includes afirst plug portion, a second plug portion, and an elongate member. Thefirst plug portion includes a first endwall and a first sidewall coupledto the first endwall. The first sidewall includes a female sectionextending in a direction along a longitudinal axis of the mechanicalplug. The second plug portion is movable relative to the first plugportion. The second plug portion includes a second sidewall, a secondendwall coupled to the second sidewall, and a seal. The second sidewallincludes a male section extending in a direction along the longitudinalaxis. The male section mates with the female section. The seal surroundsa portion of the male section. The seal is disposed in a region alongthe longitudinal axis between the second endwall and the female section.The elongate member is coupled to the first plug portion and the secondplug portion. Actuation of the elongate member moves the first plugportion and the second plug portion toward each other to compress theseal in a direction along the longitudinal axis.

In another embodiment, the disclosure provides a method of restrictingfluid flow through a conduit having an inner wall. The method includespositioning a mechanical plug in the conduit with the mechanical plug ina disengaged configuration; actuating an elongate member of themechanical plug, thereby moving a first plug portion and a second plugportion of the mechanical plug toward each other to switch themechanical plug to an engaged configuration; and compressing a seal ofthe mechanical plug, thereby pressing the seal against the inner wall toseal the conduit.

Other aspects of the disclosure will become apparent by consideration ofthe detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a mechanical plug according to anembodiment of the invention.

FIG. 2 is another perspective view of the mechanical plug of FIG. 1 .

FIG. 3 is a cross-sectional view of the mechanical plug of FIG. 1 takenalong section line 3-3 of FIG. 2 .

FIG. 4 is an exploded view of the mechanical plug of FIG. 1 .

FIG. 5 is a perspective view of the mechanical plug of FIG. 1 in adisengaged configuration.

FIG. 6 is a perspective view of the mechanical plug of FIG. 1 in anengaged configuration.

FIG. 7 is a perspective view of the mechanical plug of FIG. 1 in acompressed configuration.

FIG. 8 shows the mechanical plug of FIG. 1 within a conduit to restrictfluid flow.

FIG. 9 is a perspective view of a mechanical plug according to anotherembodiment of the invention.

FIG. 10 is another perspective view of the mechanical plug of FIG. 9 .

FIG. 11 is a cross-sectional view of the mechanical plug of FIG. 9 takenalong section line 11-11 of FIG. 10 .

FIG. 12 is an exploded view of the mechanical plug of FIG. 9 .

FIG. 13 is a cross-sectional view of the mechanical plug of FIG. 9 takenalong section line 13-13 of FIG. 10 .

FIG. 14 is a cross-sectional view of the mechanical plug of FIG. 9 takenalong section line 14-14 of FIG. 9 .

FIG. 15 is a perspective view of the mechanical plug of FIG. 9 in adisengaged configuration.

FIG. 16 is a perspective view of the mechanical plug of FIG. 9 in acompressed configuration.

FIG. 17 shows the mechanical plug of FIG. 9 within a conduit to restrictfluid flow.

DETAILED DESCRIPTION

Before any embodiments of the invention are explained in detail, it isto be understood that the invention is not limited in its application tothe details of construction and the arrangement of components set forthin the following description or illustrated in the following drawings.The invention is capable of other embodiments and of being practiced orof being carried out in various ways.

Embodiments of the invention relate to mechanical plugs. While in adisengaged configuration, a mechanical plug is insertable into aconduit, such as a sewer line, an oil pipeline, a gas line, or a watermain. The mechanical plug may be inserted through a hot tap in theconduit, for example.

In one embodiment, once inserted, an actuator member of the mechanicalplug is activated (e.g., by a technician, diver, remote operatedvehicle, or robot) to change the plug into an engaged configuration suchthat the plug is locked into place within the conduit. Once positioned,the plug is adjusted into a compressed configuration for restrictingfluid flow through the conduit by compressing an elastomeric seal. Inanother embodiment, the mechanical plug is activated from a disengagedconfiguration to the compressed configuration without a separate engagedconfiguration.

Restricting fluid flow permits repair and/or maintenance (e.g.,cleaning, patching holes, etc.) to be performed on the conduit. Invarious embodiments, the mechanical plug does not couple with fluidlines for inflation and deflation of the mechanical plug.

The mechanical plug may be made of any suitable materials known in theart. For example, the mechanical plug may be primarily made of aluminum,stainless steel, and/or plated steel. The seal of the mechanical plugmay be made of an elastomeric material, such as rubber, although theseal material can be suitably chosen based on chemical and temperaturerequirements. Generally, the materials should be suitable for most size,pressure, temperature, and chemical requirements typically necessary forrestricting fluid flow in a conduit, such as a sewer line, an oilpipeline, a gas line, or a water main. Certain components of themechanical plug could comprise other materials, such as other metals oralloys, other synthetic or natural polymers, a plastic material, a glassmaterial, a ceramic material, a biomaterial, or a composite material.

FIGS. 1-4 illustrate a mechanical plug 100 according to an embodiment ofthe invention. The illustrated mechanical plug 100 includes a first plugportion 104, a second plug portion 108, and an elongate member 112. Thefirst plug portion 104 has a first endwall 116, a first sidewall 144, aplurality of projections 120, and a plurality of locking pins 124. Thesecond plug portion 108 has a second sidewall 128, a second endwall 130,an intermediate washer 132, and a seal 136.

As shown in FIGS. 2-4 , the first endwall 116 is secured to an end ofthe first sidewall 144. The first endwall 116 and the first sidewall 144form a generally cylindrically-shaped structure that is shaped and sizedto fit within a conduit. The size (e.g., diameter) of the first endwall116 and the first sidewall 144 may be varied to fit different sizes ofconduits. In some embodiments, the shape of the first endwall 116 andthe first sidewall 144 may also be varied to fit other shapes ofconduits (e.g., square, rectangular, octagonal, oblong, etc.). In theillustrated embodiment, the first endwall 116 and the first sidewall 144are separate elements that are secured together (e.g., by theprojections 120, by welding, etc.). In other embodiments, the firstendwall 116 and the first sidewall 144 may be integrally formed as asingle piece. The illustrated first endwall 116 is a generally solidmember to restrict fluid flow, but defines apertures 145 (FIG. 4 ) toreceive other structures (e.g., the projections 120, the elongate member112) of the plug 100. The illustrated first sidewall 144 is annular inshape and defines a central opening 148 (FIG. 3 ) such that the firstsidewall 144 includes a female section extending along a longitudinalaxis 165 of the mechanical plug. The first sidewall 144 includes a flatinner wall such that the central opening 148 is cylindrical in shape.The first sidewall 144 also defines apertures 146 (FIG. 4 ) that receivethe locking pins 142. The apertures 146 communicate with the centralopening 148.

As shown in FIGS. 2 and 4 , the projections 120 extend from the firstendwall 116 and are spaced about a perimeter of the first endwall 116.In the illustrated embodiment, the projections 120 include bolts 152.Each bolt 152 includes a first end portion 152A, or head, and a secondend portion 152B. The first end portion 152A is adjacent the firstendwall 116 and configured to be engaged by a tool to rotate the bolt152. The second end portion 152B extends from the first sidewall 144toward the second plug portion 108. The bolts 152 are rotatable toadjust the distance or length that the second end portion 152B extendsfrom the first sidewall 144. Additionally, the illustrated projections120 include lock nuts 156 surrounding portions of the bolts 152. Thelock nuts 156 abut the first endwall 116 to set the length that thebolts 152 extend from the first sidewall 144. In other embodiments, theprojections 120 may include other types of projections, such asprojections that are integrally-formed with or integrated into the firstendwall 116.

As shown in FIGS. 2 and 4 , the locking pins 124 are supported by thefirst sidewall 144. The locking pins 124 are slidably received in theapertures 146 of the first sidewall 144. The locking pins 124 mayinclude three sets of locking pins 124, for example, circumferentiallyspaced about a circumference of the first sidewall 144. In certainembodiments, the three sets of locking pins 124 are spaced approximately120 degrees apart from each other. In other embodiments, the lockingpins 124 may only include three locking pins that are circumferentiallyspaced about the circumference of the first sidewall 144 such that eachset of locking pins 124 only includes a single locking pin. In furtherembodiments, the plug 100 may include fewer or more locking pins 124and/or the locking pins 124 may be unevenly spaced about thecircumference. As shown in FIG. 4 , each pin 124 includes a protrusion158 to inhibit the pin 124 from sliding completely out of thecorresponding aperture 146. The illustrated protrusions 158 extendradially from the locking pins 124.

As shown in FIGS. 3 and 4 , the second sidewall 128 includes a malesection extending in a direction along the longitudinal axis 165 of themechanical plug 100. The second sidewall 128 extends from the secondendwall 130 toward the first endwall 116. The illustrated secondsidewall 128 includes a cam surface 164 formed at end opposite from thesecond endwall 130, and a constant diameter portion 166 between the camsurface 164 and the second endwall 130. The cam surface 164 isconfigured to be inserted into the central opening 148 of the firstsidewall 144 such that the male section of the second sidewall 128 isreceived in the female section of the first sidewall 144. The camsurface 164 is further configured to engage the locking pins 124. Thecam surface 164 is obliquely angled relative to the longitudinal axis(e.g., a central axis) 165 of the plug 100, such that the cam surface164 decreases in diameter as the cam surface 164 extends into thecentral opening 148. The constant diameter portion 166 forms a flatsurface between the second endwall 130 and the cam surface 164.

The second sidewall 128 also includes a central bore 167. The centralbore 167 receives part of the elongate member 112 to selectively movethe second plug portion 108 relative to the first plug portion 104, asfurther described below.

The second endwall 130 is secured to an end of the second sidewall 128opposite from the first endwall 116. In the illustrated embodiment, thesecond endwall 130 is integrally formed as a single piece with thesecond sidewall 128. In other embodiments, the second sidewall 128 andthe second endwall 130 may be separate elements that are securedtogether (e.g., by screws, welding, etc.). The second endwall 130 formsa flange at the end of the second sidewall 128. The second endwall 130has a larger diameter than the rest of the second sidewall 128, suchthat the second endwall 130 extends radially outward from the centralcore.

As shown in FIGS. 3 and 4 , the intermediate washer 132 surrounds aportion of the second sidewall 128. In the illustrated embodiment, theintermediate washer 132 surrounds the constant diameter portion 166 ofthe second sidewall 128. The intermediate washer 132 is positioned withthe second endwall 130 on one side of the intermediate washer 132 andthe cam surface 164 on the other side. The intermediate washer 132 isconfigured to engage the projections 120 extending from the firstendwall 116. In other embodiments, the intermediate washer 132 may beomitted such that the projections 120 directly engage the seal 136, orthe intermediate washer 132 may be integrated into the seal 136.

The seal 136 is positioned around a portion of the second sidewall 128between the second endwall 130 and the intermediate washer 132. Theillustrated seal 136 includes an elastomeric, annular member surroundinga portion of the second sidewall 128. The seal 136 is configured to becompressed between the second endwall 130 and the intermediate washer132 when the intermediate washer 132 engages the projections 120. As theseal 136 compresses, the seal 136 expands radially outward to engage aninner surface of a conduit, blocking fluid flow through the conduit. Inthe illustrated embodiment, the seal 136 is a single member surroundingthe second sidewall 128. In other embodiments, the seal 136 may includemultiple discrete members positioned around the second sidewall 128and/or a different means of expansion.

With continued reference to FIGS. 3 and 4 , the elongate member 112 issupported by the first endwall 116 and extends through the centralopening 148 of the first endwall 116 to couple to the second sidewall128. In the illustrated embodiment, the elongate member 112 includes athreaded fastener 168, such as a bolt, threadably engaging the centralbore 167 of second sidewall 128. The elongate member 112 also includes ahead 169 (e.g., a bolt head) configured to be engaged by a tool (e.g., awrench, a socket, etc.) to rotate the elongate member 112. As theelongate member 112 is rotated, the elongate member 112 pulls or pushesthe second plug portion 108 toward or away from the first plug portion104. The elongate member 112 further includes a washer 170 positionedbetween the head 169 and the first endwall 116 to facilitate rotatingthe elongate member 112. In the illustrated embodiment, the elongatemember 112 is a single member extending along the longitudinal axis 165of the mechanical plug 100. Such an arrangement allows the second plugportion 108 to be moved relative to the first plug portion 104 byactuating a single element. In other embodiments, the mechanical plug100 may include different means for engaging and moving the second plugportion 108.

As shown in FIGS. 2-4 , the mechanical plug 100 may also include abypass valve 172 extending through the first plug portion 104 and thesecond plug portion 108. The bypass valve 172 selectively allows fluidflow through the first plug portion 104 and the second plug portion 108to relieve pressure from stopped fluid flow in a conduit, for example.Additionally, the bypass valve 172 allows some flow through themechanical plug 100 during installation before the plug 100 iscompletely secured within the conduit. The illustrated bypass valve 172includes a pipe (or bypass passage) 173 and a removable cap 174. Thepipe 173 extends through the mechanical plug 100. The removable cap 174is removably coupled to (e.g., threaded onto) an end of the pipe 173. Inother embodiments, the mechanical plug 100 may include other suitablebypass valves, or the bypass valve 172 may be omitted.

In certain embodiments, particularly for embodiments where themechanical plug 100 is relatively large, additional components may beincluded that aid in the transport or portability of the mechanical plug100. For example, in some embodiments, the plug 100 may include wheels.The wheels may be detachable or permanently connected to the first plugportion 104 and/or the second plug portion 108. The wheels may be, forexample, caster swivel wheels. The wheels may also be powered, such asby an engine or a motor.

In further embodiments, the elongate member 112 may be energized orpowered. For example, the elongate member 112 may include a solenoid orother type of motorized element that moves the second plug portion 108relative to the first plug portion 104. In such embodiments, themechanical plug 100 may include a processor and/or transceiver such thatthe plug 100 is capable of sending or receiving wireless signals toremotely control the elongate member 112. Additionally or alternatively,the plug 100 may include sensors (e.g., pressure sensors) and/or camerasto transmit data to a remote user.

FIGS. 5-7 illustrate operation of the mechanical plug 100. As shown inFIG. 5 , the plug 100 is in a first or disengaged configuration. In thisconfiguration, the first plug portion 104 and the second plug portion108 are coupled together by the elongate member 112, but are nottightened against each other. As such, the locking pins 124 areretracted within the first sidewall 144, and the projections 120 arespaced apart from the intermediate washer 132 so the seal 136 is notcompressed. While in this configuration, the plug 100 is positionablewithin a conduit.

FIG. 6 illustrates the mechanical plug 100 in a second or engagedconfiguration. In this configuration, the elongate member 112 isactuated (e.g., rotated) to move the second plug portion 108 toward thefirst plug portion 104. As the elongate member 112 rotates, the camsurface 164 extends into (or further into) the central opening 148 toengage the plurality of locking pins 124. The cam surface 164 pushes thelocking pins 124 outward from the first sidewall 144 to engage an innersurface of the conduit. The locking pins 124, thereby, help lock andcenter the plug 100 in place within the conduit. The elongate member 112can continue to be actuated until, for example, the projections 120 abutthe intermediate washer 132 or the cam surface 164 contacts the firstsidewall 144.

After the elongate member 112 moves the second plug portion 108 towardthe first plug portion 104, the projections 120 are tightened tocompress the seal 136. FIG. 7 illustrates the mechanical plug 100 in athird or compressed configuration. In this position, the bolts 152 canbe rotated or otherwise moved such that the second end portions 152Bpress against the intermediate washer 132. The intermediate washer 132then compresses the seal 136 against the flange formed by the secondendwall 130, causing the seal 136 to bulge radially outward. In thisconfiguration, the seal 136 engages the inner surface of the conduit torestrict fluid flow through the conduit.

In the embodiment described above, the projections 120 are moved afterthe elongate member 112 is engaged to move the second plug portion 108toward the first plug portion 104. In this case, the seal 136 is notcompressed by the plurality of projections 120 immediately while thelocking pins 124 are engaged. This arrangement may be advantageous whenit is desirable to place the mechanical plug 100 in a conduit before orwithout completely restricting fluid flow in a conduit.

In other embodiments, the seal 136 may be compressed as the elongatemember 112 is actuated. For example, the lengths of the projections 120extending from the first sidewall 144 may be set so that the second endportions 152B engage the intermediate washer 132 at the same time thecam surface 164 pushes the locking pins 124 radially outward. In such anarrangement, the lock nuts 156 may be used to set and hold the lengthsof the projections 120 prior to actuating the elongate member 112. Thisarrangement may be advantageous to more quickly and easily install themechanical plug 100 in a hard to reach location by only requiringactuation of one element (e.g., the elongate member 112).

FIG. 8 shows the mechanical plug 100 in a conduit 176 having an innerwall 180. The mechanical plug 100 is shown in the compressedconfiguration to restrict fluid flow through the conduit 176. In certainembodiments, the locking pins 124 self-center the mechanical plug 100relative to the inner wall 180, due to a directional fluid pressure inthe conduit 176. The directional fluid pressure may also furthercompress the seal 136.

FIGS. 9-12 illustrate a mechanical plug 200 according to anotherembodiment of the invention. The illustrated mechanical plug 200includes a first plug portion 204, a second body plug portion 208, andan elongate member 212. The first plug portion 204 has a first endwall216, a first sidewall 244, and two sets of locking pins 224A, 224B. Thesecond plug portion 208 has a second sidewall 228, a second endwall 230,an intermediate washer 232, and two seals 236A, 236B.

As shown in FIGS. 10-12 , the first endwall 216 is secured to an end ofthe first sidewall 244. The first endwall 216 and the first sidewall 244form a generally cylindrically-shaped structure that is shaped and sizedto fit within a conduit. The size (e.g., diameter) of the first endwall216 and the first sidewall 244 may be varied to fit different sizes ofconduits. In some embodiments, the shape of the first endwall 216 andthe first sidewall 244 may also be varied to fit other shapes ofconduits (e.g., square, rectangular, octagonal, oblong, etc.). In theillustrated embodiment, the first endwall 216 and the first sidewall 244are separate elements that are secured together (e.g., by welding,screws, elongate member 212, etc.). In other embodiments, the firstendwall 216 and the first sidewall 244 may be integrally formed as asingle piece. The illustrated first endwall 216 is a generally solidmember to restrict fluid flow, but defines apertures 245 (FIG. 12 ) toreceive other structures (e.g., the elongate member 212) of the plug200. The illustrated first sidewall 244 is annular in shape and definesa central opening 248 (FIG. 11 ). The first sidewall 244 includes a flatinner wall such that the central opening 248 is cylindrical in shape.The first sidewall 244 also defines apertures 246 (FIG. 12 ) thatreceive the locking pins 224A, 224B. The apertures 246 communicate withthe central opening 248.

As shown in FIGS. 10 and 12 , the locking pins 224A, 224B are supportedby the first sidewall 244. The locking pins 224A, 224B are slidablyreceived in the apertures 246 of the first sidewall 244. In theillustrated embodiment, the first plug portion 204 includes two sets oflocking pins 224 that are axially offset from each other. The first setof locking pins 224A are positioned closer to the first endwall 216, andthe second set of locking pins 224B are positioned closer to an end ofthe first sidewall 244 opposite from the first endwall 216. Each set oflocking pins 224A, 224B includes three pairs of locking pinscircumferentially spaced about a circumference of the first sidewall244. In the illustrated embodiment, the pairs of locking pins in eachset of locking pins 224A, 224B are spaced approximately 120 degreesapart from each other. The second set of locking pins 224B is alsocircumferentially offset from the first set of locking pins 224A. Thatis, each pair of locking pins in the second set of locking pins 224B ispositioned between two adjacent pairs of locking pins in the first setof locking pins 224A in a circumferential direction. In otherembodiments, each set of locking pins 224A, 224B may include fewer ormore pairs and/or may include single locking pins rather than pairs oflocking pins. In addition, the plug 200 may include fewer or morelocking pins 224A, 224B, the locking pins 224A, 224B may be unevenlyspaced about the circumference, and/or the locking pins 224A, 224B maynot be axially offset. As shown in FIG. 12 , each locking pin 224A, 224Bincludes a protrusion 258 to inhibit the pin 224A, 224B from slidingcompletely out of the corresponding aperture 246. The illustratedprotrusions 258 extend radially from the locking pins 224A, 224B.

As shown in FIGS. 11 and 12 , the second sidewall 228 extends from thesecond endwall 230 toward the first endwall 216. The second sidewall 228includes two cam surfaces 264A, 264B positioned adjacent an end of thesecond sidewall 228 opposite from the second endwall 230. In theillustrated embodiment, the cam surfaces 264A, 264B are formed on camrings 266A, 266B that are secured to the second sidewall 228. The camrings 266A, 266B are held in place by a stop ring 270 that is secured tothe second sidewall 228 by fasteners 271 (e.g., screws). In otherembodiments, the cam surfaces 264A, 264B may be integrally formed on thesecond sidewall 228, or the cam rings 266A, 266B may be secured to thesecond sidewall 228 using other suitable means. The cam surfaces 264A,264B are configured to be inserted into the central opening 248 of thefirst sidewall 244 and engage the locking pins 224A, 224B. Moreparticularly, the first cam surface 264A is configured to engage thefirst set of locking pins 224A, and the second cam surface 264B isconfigured to engage the second set of locking pins 224B. The camsurfaces 264A, 264B are obliquely angled relative to a longitudinal axis265 of the plug 200, such that the cam surfaces 264A, 264B decrease indiameter as they extend into the central opening 248.

An O-ring 256 is supported by the second sidewall 228 adjacent thesecond cam surface 264B. The O-ring 256 engages the inner surface of thefirst sidewall 244 to create a fluid tight seal between the secondsidewall 228 and the first sidewall 244 when the second sidewall 228 isinserted into the central opening 248.

The second endwall 230 is secured to an end of the second sidewall 228opposite from the first endwall 216. In the illustrated embodiment, thesecond endwall 230 is connected to the second sidewall 228 by fasteners260 (e.g., screws). In other embodiments, the second endwall 230 may beintegrally formed as a single piece with the second sidewall 228. Thesecond endwall 230 forms a flange at the end of the second sidewall 228.The second endwall 230 has a larger diameter than the rest of the secondsidewall 228, such that the second endwall 230 extends radially outwardfrom the second sidewall 228.

As shown in FIGS. 11 and 12 , the intermediate washer 232 surrounds aportion of the second sidewall 228. The intermediate washer 232 ispositioned between the seals 236A, 236B. The intermediate washer 232includes an outer profile that generally matches an outer profile of theseals 236A, 236B such that the seals 236A, 236B seat on the intermediatewasher 232. In other embodiments, the intermediate washer 232 may beintegrated into one or both of the seals 236A, 236B.

The seals 236A, 236B are positioned around portions of the secondsidewall 228 on opposite sides of the intermediate washer 232. In theillustrated embodiment, the plug 200 includes two seals 236A, 236B. Inother embodiments, the plug 200 may include fewer or more seals 236A,236B. The first seal 236A is positioned between the intermediate washer232 and the first sidewall 244. The second seal 236B is positionedbetween the intermediate washer 232 and the second endwall 230. Theillustrated seals 236A, 236B include elastomeric, annular memberssurrounding the second sidewall 228. The seals 236A, 236B are configuredto be compressed between the second endwall 230 and the first sidewall244 when the second plug portion 208 moves toward the first plug portion204. In particular, the first sidewall 244 engages the first seal 236Ato compress the first seal 236A between the first sidewall 244 and theintermediate washer 232. Force provided by the first seal 236A againstthe intermediate washer 232 pushes the intermediate washer 232 againstthe second seal 236, compressing the second seal 236B between theintermediate washer 232 and the second endwall 230. In the illustratedembodiment, the first sidewall 244 directly engages the first seal 236Ato compress the first seal 236A. In other embodiments, the firstsidewall 244 may indirectly engage the first seal 236A through anintermediate member. As the seals 236A, 236B compress, the seals 236A,236B expand radially outward to engage an inner surface of a conduit,blocking fluid flow through the conduit. In the illustrated embodiment,each seal 236A, 236B is a single member surrounding the second sidewall228. In other embodiments, each seal 236A, 236B may include multiplediscrete members positioned around the second sidewall 228 and/ordifferent means of expansion.

As shown in FIGS. 11 and 12 , the elongate member 212 is supported bythe first endwall 216 and extends through the central opening 248 of thefirst endwall 216 to couple to the second endwall 230. In theillustrated embodiment, the elongate member 212 includes a threadedfastener 268, such as a bolt, threadably engaging a central bore 267 ofthe second endwall 230. As the elongate member 212 is rotated, theelongate member 212 pulls or pushes the second plug portion 208 towardor away from the first plug portion 204. In the illustrated embodiment,the elongate member 212 is a single member extending along thelongitudinal axis 265 of the mechanical plug 200. Such an arrangementallows the second plug portion 208 to be moved relative to the firstplug portion 204 by actuating a single element. In other embodiments,the mechanical plug 200 may include different means for engaging andmoving the second endwall 230.

The illustrated elongate member 212 optionally includes a first handle280. The first handle 280 includes a nut 284 that threads onto thethreaded fastener 268 and a grip 288 extending outwardly from the nut284. A washer 292 is positioned between the nut 284 and the firstendwall 216. The grip 288 is configured to be grasped by a remoteoperated vehicle (ROV), such as an underwater robot. The ROV can rotatethe grip 288 to actuate the elongate member 212, moving the second plugportion 208 toward or away from the first plug portion 204. In otherembodiments, a human may grasp and rotate the grip 288 to actuate theelongate member 212.

The illustrated plug 200 also optionally includes a second handle 296attached to and extending from the first endwall 216. The second handle296 is secured to the first endwall 216 with a fastener 300 (e.g., ascrew). The second handle 296 provides a ground or stabilizer that canbe grasped by the ROV such that the ROV has leverage to actuate theelongate member 212 with the first handle 280. In other embodiments, thefirst handle 280 and/or the second handle 296 may be omitted.

As shown in FIGS. 10-12 , the mechanical plug 200 may also include abypass valve 272 extending through the first plug portion 204 and thesecond plug portion 208. The bypass valve 272 selectively allows fluidflow through the first plug portion 204 and the second plug portion 208to relieve pressure from stopped fluid flow in a conduit, for example.Additionally, the bypass valve 272 allows some flow through themechanical plug 200 during installation before the plug 200 iscompletely secured within the conduit. The illustrated bypass valve 272includes a pipe (or bypass passage) 273 and a removable cap 274. Thepipe 273 extends through the mechanical plug 200. The removable cap 274is removably coupled to (e.g., threaded onto) an end of the pipe 273. Inother embodiments, the mechanical plug 200 may include other suitablebypass valves, or the bypass valve 272 may be omitted.

The illustrated mechanical plug 200 may further include a pressure gauge304. The gauge 304 is used to measure pressure between the seals 236A,236B. In the illustrated embodiment, the gauge 304 is supported by thefirst endwall 216 and communicates with a space between the seals 236A,236B via a series of a series of channels. As shown in FIG. 13 , a pipe308 extends between the gauge 304 and the second sidewall 228. The gauge304 is in fluid communication with a first channel 312 defined in thesecond sidewall 228 via the pipe 308. A circumferential channel 316, orgroove, is formed in an outer surface of the second sidewall 228 behindthe intermediate washer 232. The intermediate washer 232 defines asecond channel 320 that is in fluid communication with thecircumferential channel 316 and, thereby, the first channel 312. Thesecond channel 320 is also in fluid communication with the space betweenthe seals 236A, 236B such that the gauge 304 can measure a pressurewithin the space. This arrangement allows the mechanical plug 200 to beused for double block and bleed processes to test, for example, theintegrity of a joint between two adjacent conduits. In the illustratedembodiment, the gauge 304 is removably coupled to the pipe 308. In otherembodiments, the gauge 304 may be omitted.

Similar to the mechanical plug 100 described above, the mechanical plug200 may also include components that aid in the transport of the plug200 and/or the elongate member 212 may be powered or remotelycontrolled.

FIGS. 15 and 16 illustrate operation of the mechanical plug 200. Asshown in FIG. 15 , the plug 200 is in a first or disengagedconfiguration. In this configuration, the first plug portion 204 and thesecond plug portion 208 are coupled together by the elongate member 212,but are not tightened against each other. As such, the locking pins224A, 224B are retracted within the first sidewall 244, and the seals236A, 236B are not compressed. While in this configuration, the plug 200is positionable within a conduit.

FIG. 16 illustrates the mechanical plug 200 in a second or compressedconfiguration. In this configuration, the elongate member 212 isactuated (e.g., rotated) to move the second plug portion 208 toward thefirst plug portion 204. As the elongate member 212 rotates, the camsurfaces 264A, 264B extend into (or further into) the central opening248 to engage the plurality of locking pins 224A, 224B. The cam surfaces264A, 264B push the locking pins 224A, 224B outward from the firstendwall 216 to engage an inner surface of the conduit. The locking pins224, thereby, help lock and center the plug 200 in place within theconduit.

When the elongate member 212 pulls the first plug portion 204 and thesecond plug portion 208 sufficiently close, the first sidewall 244 alsocompresses the first seal 236A against the intermediate washer 232,which then compresses the second seal 236B against the second endwall230, causing the seals 236A, 236B to bulge radially outward. In thisconfiguration, the seals 236A, 236B engage the inner surface of theconduit to restrict fluid flow through the conduit.

In the embodiment described above, the seals 236A, 236B are compressedas the elongate member 212 is actuated. This arrangement may beadvantageous to quickly and easily install the mechanical plug 200 in ahard to reach location, such as a vertically aligned conduit, by onlyrequiring actuation of one element (e.g., the elongate member 212).

FIG. 17 shows the mechanical plug 200 in a conduit 276 having an innerwall 278. The mechanical plug 200 is shown in the compressedconfiguration to restrict fluid flow through the conduit 276. In certainembodiments, the locking pins 224A, 224B self-center the mechanical plug200 relative to the inner wall 280, due to a directional fluid pressurein the conduit 276. The directional fluid pressure may also help furthercompress the seals 236A, 236B.

In the embodiment described above, the plug 200 was suitably operable upto a pressure of (at least) 400 psi.

The mechanical plugs described herein have the distinct advantage thatthere is no need to transport and couple fluid lines to the plug tocreate a fluid-tight seal. A diver or underwater robot (e.g., ROV), forexample, may install the mechanical plug without assistance fromtechnicians external to the conduit. As detailed above, a singleactuator member can seal or unseal the mechanical plug, and the plug isself-centering for relatively simple installation. In certainembodiments, the mechanical plug is completely reusable and, ifnecessary, the seal is simple to replace. The mechanical plug is alsodesigned to be scalable in size and otherwise customizable for severeconditions. For example, the plug is excellent for subsea applicationsand/or remote placement.

Various features and advantages of the invention are set forth in thefollowing claims.

What is claimed is:
 1. A method of restricting fluid flow through aconduit having an inner wall, the method comprising: positioning amechanical plug in the conduit with the mechanical plug in a disengagedconfiguration, the mechanical plug including a first plug portion havinga female section, a second plug portion having a male section receivedin the female section, a threaded fastener extending through the firstplug portion and engaging the second plug portion, and a seal supportedon the male section of the second plug portion; rotating the threadedfastener of the mechanical plug to move the first plug portion and thesecond plug portion toward each other and transition the mechanical plugto an engaged configuration; and compressing the seal on the malesection of the second plug portion, thereby pressing the seal againstthe inner wall to seal the conduit.
 2. The method of claim 1, furthercomprising pushing a plurality of locking pins laterally outward toengage the inner wall and center the mechanical plug in the conduit. 3.The method of claim 2, wherein the pushing step occurs during theactuating step and before the compressing step.
 4. The method of claim2, wherein pushing the plurality of locking pins includes engaging theplurality of locking pins with a cam surface on the male section of thesecond plug portion as the first plug portion and the second plugportion move toward each other.
 5. The method of claim 1, whereinrotating the threaded fastener includes grasping a first handle coupledto the threaded fastener.
 6. The method of claim 5, further comprisinggrasping a second handle extending from the mechanical plug whilerotating the threaded fastener.
 7. The method of claim 1, wherein theseal is a first seal, and further comprising compressing a second sealon the male section of the second plug portion, thereby pressing thesecond seal against the inner wall to seal the conduit.
 8. The method ofclaim 7, wherein compressing the first seal includes compressing thefirst seal between the first plug portion and an intermediate washer,and wherein compressing the second seal includes compressing the secondseal between the intermediate washer and the second plug portion.
 9. Themethod of claim 7, further comprising measuring a pressure within aspace between the first seal and the second seal.
 10. The method ofclaim 1, further comprising allowing fluid flow through the first plugportion and the second plug portion via a bypass valve.
 11. A method forrestricting fluid flow through a conduit having an inner wall, themethod comprising: positioning a mechanical plug in the conduit with themechanical plug in a disengaged configuration, the mechanical plugincluding a first plug portion, a second plug portion, an elongatemember, a first seal, and a second seal spaced apart from the firstseal; actuating the elongate member of the mechanical plug to transitionthe mechanical plug to an engaged configuration; compressing the firstseal and the second seal of the mechanical plug between the first plugportion and the second plug portion, thereby pressing the first seal andthe second seal against the inner wall to seal the conduit; andmeasuring a pressure within a space between the first seal and thesecond seal.
 12. The method of claim 11, wherein compressing the firstseal and the second seal includes compressing the first seal between thefirst plug portion and an intermediate washer, and compressing thesecond seal between the intermediate washer and the second plug portion.13. The method of claim 12, wherein the intermediate washer defines achannel for measuring the pressure between the first seal and the secondseal.
 14. The method of claim 11, wherein measuring the pressureincludes measuring the pressure via a pressure gauge supported on themechanical plug.
 15. The method of claim 14, wherein the pressure gaugeis supported by the first plug portion and in fluid communication with achannel formed in the second plug portion.
 16. A method for restrictingfluid flow through a conduit having an inner wall, the methodcomprising: positioning a mechanical plug in the conduit with themechanical plug in a disengaged configuration, the mechanical plugincluding a first plug portion, a second plug portion, an elongatemember coupled to the first plug portion and the second plug portion,and a seal; actuating the elongate member of the mechanical plug totransition the mechanical plug to an engaged configuration; compressingthe seal between the first plug portion and the second plug portion,thereby pressing the seal against the inner wall to seal the conduit;and allowing fluid flow through the first plug portion and the secondplug portion via a bypass valve.
 17. The method of claim 16, wherein thebypass valve includes a pipe extending through the first plug portionand the second plug portion.
 18. The method of claim 17, whereinallowing fluid flow through the first plug portion and the second plugportion includes removing a cap from an end of the pipe.
 19. The methodof claim 16, the allowing step occurs before the actuating step and thecompressing step.
 20. The method of claim 16, wherein the allowing stepoccurs after the actuating step and the compressing step.